Assume the terminal payoff at the node (4) is less than −4. Do we need to expand node (5) and (6)? Answer yes or no, then explain your answers.
Why don't we have to because of a-b pruning?
 

(a) (b) de dd (1) ce (2) a df dd cd b (3) bd d E ae (4) f ad af (5) ac (6) igure 1: (a) A map where the cost of every edge is 1. Initially the pursuer P is at node b and the evader E is at ode d. (b) A partial game tree for this map. Each node is labeled with the P. E positions. P moves first.